Determining the location of a moving object within a beacon field where beacons have known positions involves optimizing a vector solution for the position of the object relative to at least two beacons of the array. While numerous computational methodologies exist for triangulation or trilateration to determine range measurements of the object, a problem common to various methodologies is environmental signal interference that lessens the accuracy of object position. As object position accuracy is critical to achieving many of the efficiencies of autonomously operating robotic vehicles, many such applications have been hindered by the inability to inexpensively and accurately locate the moving object within a beacon field.
This problem is shown schematically with respect to prior art FIG. 1 where a moving object denoted at “A” is within an array of beacons denoted at B, C, E, H, and I. As shown graphically in prior art FIG. 1, it is appreciated that a beacon field would not always have uniform spacing between beacons within the array.
Each range measurement is acquired between two radios. The first radio on object A requests a range from radio beacon B. Radio beacon B responds to radio A, where the time of flight of the request-response sequence is used to determine the distance from A to beacon B. Likewise, an accurate time of flight measurement is obtained between A-H and A-I.
The range measurement is less accurate when the radio signals must penetrate objects in the line of sight between them. Radio beacon C receives a request from radio A. The range measurement is less accurate because the radio waves have to penetrate obstacle D.
In worse case scenarios, the signal travels indirectly between radio A and radio E, bouncing off the surface of object G. The resulting range measurement does not represent the distance between radios A and E anymore, yet in a conventional range measurement system inaccurate range measurement signals A-G-E and A-D-C are nonetheless used to compute object position.
Thus, there exists a need for a system and process for discounting accurate inputs associated with obstacle impaired beacons and determining range measurement for a moving object within a beacon field. There further exists a need for such a system that is robust and inexpensive to implement, as well as being potentially used by multiple objects navigating within the beacon field.